Outboard marine drive



INVENTORS Zeal 611' Donald Pitt BY L. O. LEAVITT ETAL OUTBOARD MARINEDRIVE Filed April 30, 1958 April 11, 1961 Man/2, L iddy, Daniels & Marc/ATTORVEYS United States Patent 9 OUTBOARD MARINE DRIVE Lyman 0. Leavittand Donald -Pitt,'Salt Lake City, Utah, asslgnorsto Anchor Boat & Steel430., Salt Lake City, Utah, a corporation of Utah Filed Apr. 30, 19158,Ser. No. 731,926

1 Claim. (Cl. 115-34) This invention relates to marine drives .asadapted for small boats and launches, and ,moreparticularly tooutboard-type drives for use with inboard engines.

An object of the present invention is to provide a novel and improved,outboard-type screw or propeller drive mechanism for use with aninboardengine, said drive having a quiet, powerful and reliable belttype of transmission extending below the water line and characterized bygreatly reduced drag and resistance which is offered to thepassage ofwater past the hull and drive mechanism.

In the specific illustrated embodiment of the invention the powertransfer is accomplished by a toothed beltof the type commonly used forautomotive timing drives, and in accomplishing the above object weprovide anovel housing for enclosing the said belt, consisting of twovertically extending spaced hollow legs which contain and houserespectively the ascending and descending portions of the belt drive.Between the spaced housing legs a passage .of relatively large areaexists, through which water may flow freely and with but .littleresistance, thereby greatly reducing the drag of the-drive housing. Inconjunction with such housing we further ,provide .ahollow screw or.propeller shaft carrying the pulley for the driving belt, said shaft.by virtue of its hollow construction permitting thepassage of .watertherethrough, thus further decreasing the resistance or drag of thedrive. mechanism.

A further object of the present inventionis to provide a novel andimproved propeller mounting and torqueimparting means, in conjunctionwith the .said hollow propeller shaft,.by which the propeller isnormally driven without slippage for movingthe boat through the water,yet if the propeller should strike an object while being driven, it mayimmediately .halt in its iturningor slow down 'as required, while the.engine and remainderof .the drive mechanism continue delivering ;power,thereby sto prevent damage to the propeller.

A feature of the invention resides in the provision of improved outboarddrive meanscharacterized by minimum drag, and improved propeller 'torqueimparting means as above characterized, which are extremely simple inconstruction, reliable in operation and economical to fabricate.

Other features and advantages will hereinafter appear.

In the drawings accompanying this specification, similar characters ofreference are used to designate like components throughout the severalviews, in which:

Figure 1 is a side elevational view of a small boat or launch, havingthe improved outboard drive of the invention attached to it.

Fig. 2 is a fragmentary rear elevational view of the outboard drivestructure which is incorporated in the boat shown in Fig. 1.

Fig. 3 is a side elevational view of the outboard drive structure ofFig. 2.

Fig. 4 is a fragmentary exploded view of the pulley and belt drivecomponents utilized in the outboard drive of the present invention.

Fig. 5 is a fragmentary axial sectional view of the propellershaft andyieldable friction drive between the propeller hub and shaft,as,provided by the invention.

Fig. 6 is a'fragmentary axial sectional .view showing a .universal jointtype of driving coupling or connection, as provided :between the inboardengine and the outboard .drive of the present invention.

Referring first to Fig. 1 there is shown a usual type of small boathaving a hull 10 in the stern of which there is mounted an inboardmarine engine 12. The engine 12 has a splined hollow drive member 13extending rearwardthrough a suitable opening in the stern of the hull10. 'Carriedby the drive shaft 13 is a universal joint or drivingconnection 15, Fig. 6, which has a splined output shaft .17 adapted to:be received in a hollow jack shflt 18 disposed within an outboard drivehousing, specifically an .upperhousingportion .19. The universal jointor driving rconnection .15 may also have a splined input shaft 26, .Fig.'6,-a'dapted :to be receivedvin the drive member 13 carried; by theengine "12.

.According to thepresent invention we provide a novel ;andzimprovedoutboard drive mechanism of the type employing an endless belt'or-chain,and in conjunction therewith providea uniquethousing means, including alower :housingzportion.indicated at 22 in Figs. 1, 2 and 3, said:housing portion being-especially arranged to enclose the driving beltor chain while at the same time providing .a rminirnumdrag or-resistanceto the fiow of water past the thrill Iii.

:Referring ,to Figs. 2-4, the upper housing portion 19 .mounts thehollowjack shaft 18 on suitable bearings (not rshown). The shaft 18carries apulley or sprocket 24 of the type .adaptedto mesh with a timingbelt 25 of conventional design or structure. The lower housing portion22 of: the :outboard drive carries a propeller shaft 26 in suitablebearings (not shown), such propellershaft also having 'a pulley :orsprocket wheel 27 adapted to mesh -withthe timing'belt 25.

.Referring"particularly to Fig.2, the improved housing construction alsoincludes an intermediate housing portion constituted of -a pair ofvertically extending, spaced hol- .low legs .28 ,and29, through whichthe ascending and descending portions of the timing belt or chain 25pass in traveling-between thepulleys or sprockets 2.4 and 27.

Disposed between the lower extremities of the hollow legs28 and 29 isthe circular or cylindrical lower housing portion 22, having ;a forwardextension 31 in which the propeller shaft 26 isdisposed, together withthe bearings for such shaft. The spaces within the hollow legs 28 and'29communicate withzthe interior of the cylindrical housing=portionsl22, as will be readily understood, for the -purpose:of.permittingpassage of'the driving belt or chain 125. Theilegsi28;and.29are watertight, as are the joints where-they attachrtothe upperjhousingportion 19 and the lower housing portion 22. It will be understood thatwhere the propeller shaft 26 extends forwardly out of the cylindricalhousing portion 31 a suitable packing and sealing arrangement isprovided, in conjunction with the forward bearing for the propellershaft, thereby to prevent entrance of water into the housing, where suchwater might come in contact with the driving timing chain 25 and lowersprocket 27.

Further, in accordance with the present invention, the propeller shaft26 is made hollow and has an appreciable diameter, thereby to permit thepassage of water through the propeller shaft and through the hub 33 ofthe propeller or screw 34 which is carried on the forward extremity ofthe shaft 26. Thus, the propeller hub 33 and the shaft 26 provide aminim-um of resistance to the flow of water past the hull 10, and alsothe same is true of the lower housing portion 22 and intermediatehousing portion of the outboard drive, since a relatively large space 36exists e 3 between the depending hollow legs 28 and 29 through whichspace water may flow with only slight impedance. Further, in accordancewith the present invention, we

'provide a novel torque-transmitting device between the hub 33 of thepropeller 34 and the propeller shaft 26,

said device normally driving the propeller at its proper rate of speedto propel the boat forwardly, but permaterial such as resilient andflexible rubber or rubberlike substance.

The friction sleeve 38 is contained within the propeller hub 33 andrests against a rear internal shoulder 40 provided in said hub. At itsfront end, the friction sleeve 38 is engaged by a nut 41 which isthreaded on the propeller shaft 26. The nut 41 has a shoulder 42 adaptedto engage the front edge of the propeller 33, and

the propeller shaft 26 has an annular external shoulder 44 engaging therear of the hub 33, thereby to securely retain the propeller 34 on theshaft 26 while at the same time permitting a controlled slippage of thepropeller when it strikes an object in the water.

By regulating the nut 44, the amount of compression existing in therubber sleeve 38 may be varied, thereby to vary the friction between thepropeller 34 and the shaft 26, and such friction is adjusted so thatnormally it is great enough to cause a proper driving of the propellerduring normal operation of the boat and engine, yet not so great thatthe propeller cannot slip and come completely to a stop when it strikesan object in the water, even though the engine and the drive shaftsconnected thereto continue to turn. Thus, the propeller 34 is protectedat all times by this frictional drive which permits slippage underabnormal conditions, and this is an important feature of the invention.

Moreover, it will be observed that such controlled slippage of thepropeller is effected by an extremely simple and inexpensive frictiondevice, comprising the rubber sleeve 38.

Referring to Fig. 6, the universal joint type of coupling includes abearing 50 for the spline-d shaft 17, said bearing being carried by theupper housing portion 19 of the outboard drive. The universal jointincludes a link 51 which is pivotally connected between yokes 52 and 53respectively secured to the splined shafts 17 and 20. A flexible rubberboot 55 encloses the universal joint 15 and seals the same againstentrance of water and other foreign matter.

It will now be readily understood that by the foregoing and inaccordance with the invention we have provided a novel and unique, quietyet powerful and reliable outboard drive means for small boats, launchesand the like,

the said drive means being characterized by an extremely smooth actionas effected by the use of a timing chain or similar belt type of drive,and being further characterized by presenting a minimum of resistance tothe flow of water past the hull 10. Such minimum resistance is effectedby the unique hollow-leg design of the intermediate portions 28 and 29of the outboard drive housing, in conjunction with the hollowconstruction of the shaft 26. Moreover, in conjunction with suchstructure we further provide a novel friction mounting for the propeller34, which permits the propeller to slip and come to a completestandstill if it should strike an immovable object while turning in thewater, even though the engine and the accompanying drive shafts continueto rotate at normal speeds.

The above structures as provided by the invention are extremely simpleand economical to fabricate while at the same time providing for greatreliability and flexibility in .below the said upper portion, and anintermediate connecting portion between said upper and lower portions;

a drive wheel disposed in said upper housing portion at a point abovethe water line of the housing; a propeller shaft and driven wheeldisposed in said lower housing portion at a point below the water lineof the housing, said propeller shaft having an appreciable diameter andbeing hollow with open ends thereby to permit the passage of water.through the center of the propeller shafts; a belt extending between andpassing around said wheels, said intermediate housing portion comprisinga pair of spaced,

slender, hollow members extending vertically between the upper and lowerhousing portions and enclosing respectively the ascending and descendingportions of the belt, the space between said hollow members being freeof obstruction from front to rear, thereby to make possible theunimpeded passage of water between the members.

References Cited in the file of this patent UNITED STATES PATENTS1,845,712 Jacques Feb. 16, 1932 2,679,909 Kiekhaefer June 1, 19542,722,193 Brindley Nov. 1, 1955 2,751,987 Kiekhaefer June 26, 19562,809,605 Russell Oct. 15, 1957 FOREIGN PATENTS 311,674 Great BritainMay 10, 1929

